Patent attributes
A valve drive (1) of an internal combustion engine which is used to actuate a gas exchange valve (6) is provided. Displacement of the valve takes place when a cam (9) is lifted and when a hydraulic force applying device (12) is lifted. A piston (13) of the force applying device can be displaced from a first end position (A) to a second end position by feeding a hydraulic medium, which can be pressure-adjusted, from a hydraulic medium line (24) into a pressure chamber (21). The pressure chamber (21) can be connected to the hydraulic medium line (24) via a shut-off element (20) which is open towards the pressure chamber (21) and which is arranged in the housing (15) and also by means of at least one passage (26) in the housing (15). The passage (26) is at least partially blocked by an external casing surface (16) of the piston (13) in the first end position (A) thereof.